Platelet-activating factor (PAF) has recently been identified as an acetyl glyceryl ether phosphoryl- choline (AGEPC), i.e., 1-O-hexadecyl/octadecyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (Hanahan D. J., et al., J. Biol. Chem. 255:5514, 1980). Even before its chemical identification, PAF had been linked to various biological activities and pathways making it one of the important mediators responsible for a variety of physiological processes including activation or coagulation of platelets, pathogenesis of immune complex deposition, smooth muscle contraction, inflammation, hypotension, shock, pain, edema as well as respiratory, cardiovascular and intravascular alterations. Since these physiological processes are in turn associated with a large group of diseases, for example, inflammatory disease, cardiovascular disorder, hypotension, shock, psoriasis, allergic and skin diseases, asthma, lung edema, peptic or stomach ulcer, dental pain, and adult respiratory distress syndrome, more and more scientific investigation has been focused on the search of a PAF antagonist or inhibitor for treating or preventing these common diseases.
The compounds of the present invention are specific PAF antagonists. They are similar to a subclass of compounds called lignans which characteristically contain two phenylpropyl groups bonded at the .beta.-carbon. Tetrahydrofuran (THF) derivatives can exist in eight different stereochemical configurations as shown in Scheme I. ##STR2##
We have been able to prepare all the possible isomers of the tetrahydrofuran lignan analogs with different substituents and found that activity is stereospecific.
Accordingly, the present invention is directed to the preparation of the most potent isomers of known or novel tetrahydrofuran derivatives as PAF antagonists and use them for the treatment of various diseases including prevention of platelet aggregation, hypotension, inflammation, asthma, lung edema, adult respiratory distress syndrome, various shock syndromes, cardiovascular disorders and other related skeletal-muscular disorders, graft-host rejection, nephritis, pancreatitis, and lupus.
The present invention is also directed to acceptable pharmaceutical compositions containing one or more of the tetrahydrofuran derivatives and/or analogs as the active ingredient. As PAF antagonists, these novel compositions should be effective in the treatment of various skeletal-muscular related diseases.
The present invention is also directed to a method of treatment comprising the administration of a therapeutically sufficient amount of these PAF antagonists to a patient suffering from various skeletal-muscular disorders including inflammation, e.g., osteoarthritis, rheumatoid arthritis and gout, hypotension, shock, psoriasis, allergic or skin diseases, asthma, pain especially dental pain, peptic or stomach ulcer, lung edema, adult respiratory distress syndrome or cardiovascular disorders, graft-host rejection, nephritis, pancreatitis, and lupus.